Fuel consumption in a vehicle, and perhaps especially possibilities of reducing fuel consumption, are becoming more important for a vehicle owner as fuel prices increase. In addition to a reduced fuel cost for the owner, there follows a reduced environmental impact with reduced fuel consumption in the vehicle, since the vehicle's exhaust is approximately proportionate to the fuel consumption. In addition, there is no need to stop and refuel as often, which causes a reduced time when the vehicle is at a standstill and thus a more time efficient transport.
Fuel consumption for the vehicle is impacted by energy losses, such as for example energy loss due to rolling friction or combustion efficiency etc. However, the vehicle's fuel consumption is also impacted by factors dependent on how the driver is driving, for example braking losses, which are directly related to a driving manner. Another example is motor friction which is related to how the driver changes gears in the form of gear selection, shift point (i.e. at which engine speed one changes gears), and number of shift steps (i.e. the number of gears, if any, which are skipped when shifting gears).
With existing solutions it is difficult to investigate why a certain vehicle consumes more fuel than another, similar vehicle, even though they are driving along the same or similar road sections. This difference in fuel consumption may be due to differences in driving manner between the respective vehicle driver. It may also be due to increased friction in one of the vehicles, for example because of unnecessarily high rolling resistance as a consequence of low air pressure in the tyres, defective wheel bearings, improper wheel alignment, inappropriately chosen tread or another similar reason. It is thus difficult to discern how large a part of the respective vehicle's fuel consumption may be attributable to driver behaviour and how much may be attributable to vehicle related factors.
If the reason for the higher fuel consumption may be attributable to poor driver behaviour, this may be subject to measure packages in the form of targeted training, and/or incentives in the form of bonus programmes which reward drivers experiencing low fuel consumption. However, this becomes misdirected, for example in the example above, if the vehicle with the higher fuel consumption has a higher fuel consumption resulting from non-driver dependent increased friction as a consequence of any of the reasons mentioned above.
Another problem with high driver-related fuel costs is that these are often related to increased costs of repairs and maintenance, since a vehicle which is driven aggressively consumes more fuel while it is exposed to greater wear and tear, with increased costs of repairs and maintenance as a consequence. In addition to the direct repair cost, a transport vehicle suffers a loss of income for the duration that the vehicle is in a garage, which is of course unfavourable for its owner.
In addition, one may suspect that a driving style with high fuel consumption, for example through fast acceleration, high cruising speed and heavy braking leads to an increased risk of traffic accidents which, in addition to the potential personal suffering which may arise, may lead to further garage repairs and thus associated loss of income.
It is therefore important to be able to detect and reduce driver related high fuel consumption from several perspectives. However, it is difficult to prove how large a part of the fuel consumption is attributable to the driver's fuel demanding driving style, and how large a part is attributable to other factors, such as hilly terrain, heavy load, friction losses or traffic signal intensive urban environments at rush hour.
In addition, cases are conceivable where an energy loss analysis quickly becomes very complex and unintelligible, since several factors come into play and impact the energy losses.
It is therefore difficult to identify and overcome the cause of an increased fuel consumption in a vehicle.
Also, it is not possible to analyse and detect the reason for a change in the vehicle's fuel consumption seen in a longer perspective. Although it is possible to conclude, for example, that the fuel consumption has changed by studying fuel consumption per driven length unit for a longer period of time, it is difficult to draw any direct conclusion from this insight.
There is also a need, with the objective of reducing fuel consumption, of an aid for the driver in order to understand the connection between driving style and fuel consumption. Pursuant to prior art technology, it is possible to keep a log of fuel consumption and driving distances, but again there are several diverging explanation models for differences over time, such as height difference during the driving distance, friction loss, varying load weight etc., in addition to the driver's driving style. This makes it difficult for the driver to understand the direct connection between, for example, gear selection and gear stage selection when driving a vehicle with a manual gearbox, and fuel consumption.
Another need which has arisen is an aid, for example for an owner of a vehicle park, a vehicle garage or for a vehicle manufacturer who carries out a final test of the vehicles before delivery, of locating a fault related to an increased energy loss and thus an increased fuel consumption in a vehicle.
It may be concluded that there remains much to be done in order to reduce fuel consumption in vehicles.